The severity of atherosclerosis at the carotid artery bifurcation is correlated with the occurrence of stroke..sup.1,2 Since most strokes associated with carotid atherosclerosis can be prevented by surgical or non-surgical treatment.sup.3, the identification and monitoring of carotid disease is important for the management of patients at risk of stroke. Currently, conventional means of diagnosing and assessing the progression of atherosclerosis involve either determining the degree of stenosis with x-ray angiography or MRA, or with techniques which are sensitive to abnormalities in blood flow rate, such as Doppler ultrasonography. Unfortunately, none of these known techniques provide a clear three-dimensional (3-D) image of the target tissue in a manner which allows for the non-invasive and detailed view of the blood vessels. Moreover, none of the known techniques provide detailed visualization of the lumen surfaces of blood vessels within the body.
It is therefore an object of the present invention to provide a novel method, based on 3-D ultrasound, which is non-invasive and provides detailed three-dimensional views of internal luminal surfaces of blood vessels. An important task in the development of such a technique is the segmentation (i.e., extraction) of vessel surfaces from ultrasound images for the purposes of visualization, therapy planning, and volumetric measurements. Deformable surface models have become particularly useful tools for this method..sup.4